Field
The present invention relates to a manufacturing method of a touch screen panel including a touch sensing sensor.
Discussion of the Background
A display device such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, an electrophoretic display, etc. includes a field generating electrode and an electro-optical active layer. For example, the OLED display includes an organic emission layer as the electro-optical active layer. The field generating electrode is connected to switching elements, such as a thin film transistor and the like, configured to receive a data signal, and the electro-optical active layer is configured to convert the data signal into an optical signal to display an image.
A display panel of the display device may include a heavy and fragile glass substrate, and the display device may have some limitations in portability and use in a large screen display. Accordingly, a flexible display device may include a plastic substrate, which is light, strong against impacts, and flexible, as a substrate of the display panel.
The display device may further include a touch sensing function for interaction with a user, in addition to a display function. A touch sensing function is configured to receive touch information, including whether an object is approaching and/or touching a screen. The touch position may be detected by sensing changes in pressure, charge, light, and the like that are applied to the screen of the display device in response to a user writing characters or drawing figures by approaching and/or touching the screen using a finger and/or a touch pen. The display device may be configured to receive an image signal in response to the touch information and display an image.
The touch sensing function may be implemented using a touch sensing sensor. The touch sensing sensor may have various types, such as a resistive type, a capacitive type, an electromagnetic type (EM), an optical type, etc.
For example, the resistive type of touch sensor may include two electrodes facing and separated from each other. When a pressure from an external object is applied, the two electrodes may contact each other. When the two electrodes contact each other, change in voltage caused by change in resistance at the touch position can be detected such that the touch position and the like are determined.
The capacitive type of touch sensing sensor includes a sensing capacitor including a plurality of sensing electrodes configured to transmit a detection signal, and is configured detect change in capacitance of the sensing capacitor or an amount of charges charged in response to a conductor such as a finger approaching the touch sensing sensor, thereby determining whether the touch occurred or not and the touch position. The capacitive type of touch sensing sensor includes a plurality of touch electrodes disposed in the touch sensing area and signal-transmitting wires connected to the touch electrodes.
The signal-transmitting wires are configured to transmit a sensing input signal to the touch electrodes, and/or to transmit a sensing output signal of the touch electrodes to a sensing signal controller.
In a flexible display device, the touch sensing sensor is formed in a separate touch screen panel and attached to the flexible display device as an add-on cell type.
When a touch screen panel is formed to have a plurality of layers, a process for forming connecting portions of a touch sensing sensor is added, thereby reducing fabrication yield and increasing cost.
Also, since the connecting portions are formed as minute patterns, steps may be generated, and etching process may leave residues which may result in corrosion.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.